The present invention relates to a composite solid propellant with a stable burning rate on the basis of ammonium perchlorate, telomeric polybutadienes or copolymers of butadiene and acrylonitrile with terminal functional groups or functional groups statistically distributed along the chain, which are hardened with corresponding hardeners into rubber--elastic binders, finely pulverized metals, such as magnesium, aluminum and zirconium and/or semi-metals, such as boron and silicon, and optionally, plasticizers and burning rate moderators.
The solid propellants which are are used as energy sources for rockets usually contain the oxygen required for combustion in the form of solid oxidizers. In contrast thereto, in air-breathing boosters, oxygen from the air is used with simultaneous employment of a strongly under-balanced composite propellant. A strongly under-balanced composite propellant is one where the amount of oxidizer is greatly insufficient to oxidize the finely-pulverized metals. A significant increase in output or range is thereby made possible, because in place of solid oxidizers, additional fuel can be carried. If this fuel partly consists of the metals magnesium, aluminum or zirconium or the semi-metals, such as boron, propellants are obtained which, when burned with air, are far superior not only over the conventional rocket propellants but also over hydrocarbon/air systems, such as kerosene/air, for example.
Such a superiority comes into play only if during the combustion of the propellant a good combustion effect degree is also achieved. In these cases difficulties arise, especially when large amounts of boron or zirconium are used, which threaten to cancel out the above-mentioned advantages.